Which substance is not found in gastric juice?

Which of the following is found in the cavities of bone? periostreum endostreum fibrous tissue bone marrow

What a self improvement for a busy person who had difficulty finding time to exercise/ dropping out of clubs and activities/ refusing social invitations from friends/ scheduling daily invitation activity/ sleeping fewer hours at night

During a formal discussion in his science class, kai will be speaking about the important of exercise. what is the best advice he can follow to be a prepared speaker